docs: def delete(self, key=None):
          """Deletes the given key, or the whole bucket."""
  
          # Delete the whole bucket.
          if key is None:
              # Delete everything in the bucket.
              for key in self.all():
                  key.delete()
  
              # Delete the bucket.
              return self._boto_bucket.delete()
  
          # If a key was passed, delete they key.
          k = self.key(key)
          return k.delete()